This invention relates to novel clarified hydrocolloids which ubstantially retain the physical properties of unclarified colloids. The invention also pertains to a novel process for making the clarified hydrocolloids.
Hydrocolloids made from naturally occurring gums are used extensively in the food, pharmaceutical and cosmetics industries. Sols of most such hydrocolloids are opaque or translucent. When such hydrocolloids are clarified, the cost is usually uneconomical or there is inevitably a loss in the physical properties of the hydrocolloids compared to the unclarified colloids. This can, for example, include substantial loss in viscosity. Examples of naturally occurring gums used in making hydrocolloid sols are konjac, guar, locust bean and xanthan.
Konjac Glucomannan:
Konjac glucomannan, the first word sometimes spelled xe2x80x9ckonjakxe2x80x9d, is an acetylated glucomannan obtained from the tubers of the tropical plant, Amorphophallus konjac, commonly called xe2x80x9cDevil""s Tonguexe2x80x9d because of its high content of oxalic acid. The konjac tuber is harvested following two or three year""s growth, after which it has a diameter of 4-6xe2x80x3. Processing steps include slicing, placing the slices on racks, sun or open fire drying, pulverization, dry or wet milling to remove the oxalic acid and some of the starch content which adheres to the konjac sacs, followed by sifting or air classification. These oval sacs are about 2 mm long and are composed mostly of konjac glucomannan encased in a proteinaceous membrane. Starch granules adhere to the membrane and much of these can be removed by a 30% alcohol (aq) wash. Native konjac glucomannan has a wide variation of acetyl content since it is both a storage and a structural polysaccharide. and semiarid regions of India and Pakistan. Guar is grown principally as a food crop for animals and as an ingredient in human foods and pharmaceuticals. The guar galactomannan is the major component in the seed endosperm, while the germ portion is mainly protein. In its commercial form, guar gum contains a significant number of impurities, including husks and other cellular debris, with the guar galactomannan comprising only about one-third of the product.
The guar galactomannan is composed of a backbone of (1xe2x86x924)-linked xcex2-D-mannopyranosyl units with single xcex1-D-galactopyranosyl units connected by (1xe2x86x926) linkages, with the ratio of galactose to mannose being about 0.55. There are many galactomannans in nature, each varying in this ratio which determines physical and chemical characteristics. Guar galactomannan is soluble in water to form viscous solutions. The actual viscosity values depend upon both the molecular weight and the purity. Guar gum imparts viscosity even in high ionic strength environments. Like konjac and locust bean gum, guar reacts synergistically with xanthan to form very viscous sols and/or gels, depending on proportions and concentrations. It also reacts with alkaline borate to yield amorphous gels.
Guar has numerous applications, some of which have been supplanted by guar derivatives. These range from oil drilling products to textile printing and dyeing to foods, cosmetics and pharmaceuticals.
Locust Bean Gum (Galactomannan):
Locust bean, carob, gum is a galactomannan polysaccharide obtained from the evergreen leguminous tree, Ceretonia siliqua L., which grows extensively in Spain is also cultivated in Italy, Cyprus and other Mediterranean countries. Locust bean gum is the refined endosperm of the seed and in its commercial forms locust bean gum contains a significant number of impurities, such as husk residue and cellular debris, depending on the grade.
Locust bean gum, like guar is a galactomannan having the same basic structure. However, there are considerably fewer galactose side-chains in the locust bean galactomannan. The galactose to mannose ratio is 0.25, compared with guar""s The more acetylated forms of the konjac glucomannan are water-soluble and the more deacetylated forms are water-insoluble. This is a simplistic statement, however, since a whole spectrum exists with respect to degree of acetylation with some of the soluble species on the edge of insolubility and minor changes in environment, such as salt concentration, excessive heating, removal of protective hydrocolloids or other molecules, etc., can lead to insolubilization.
Crude konjac flour, the most common commercial form, is a well-known foodstuff in China and Japan and has recently gained FDA approval in the U.S. as a fat replacer in meat. This application is based on the fact that when konjac glucomannan is heated with alkali, about pH=xcx9c7.5-11, deacetylation occurs and the resulting gel product is water insoluble and thermostable. The deacetylated gel or paste, commonly called xe2x80x9ckonnyakuxe2x80x9d can even be fried at temperatures around 400xc2x0 F. without melting or decomposing. If the gel formed by deacetylation is frozen and thawed, a tough, coherent spongeous mass is formed. Deacetylated konjac-containing films, foams, beads, and other forms can be prepared.
Konjac reacts with borate ion at alkaline pH to form amorphous gels as well as reacting synergistically with xanthan to form elastic gels.
As expected, there are numerous impurities in the crude, unclarified konjac. These include insoluble starches, cellulose, and nitrogen-containing impurities including proteins, many of which are derived from the konjac sac membrane. While crude konjac flours have numerous applications, as foods, as a soluble fiber source, as a fat replacement in meats, etc., the clarified form is preferable and in some applications, essential, for such applications as clear dessert gels, as a viscosifier or thickening agent for clear fluids, as clear capsules, films that are free from particulates, clear cosmetics (lotions and possibly gels in combination with clarified xanthan or borate), etc.
Guar Gum (Galactomannan):
Guar gum is a galactomannan polysaccharide obtained from the seed of the legume Cyanopsis tetragonolobus, an annual plant that grows mainly in arid 0.55. This lower degree of branching is responsible for differences in properties, especially solubility. While guar is mostly soluble in cold water, locust bean gum is not. Dispersions must be heated to about 85xc2x0 C. to achieve full viscosity. Weak gels are formed when hot sols of locust bean gum are allowed to cool quiescently. Locust bean gum will gel in the presence of borate ion at alkaline pH. It will react synergistically with xanthan to form a gel and will impart elasticity to agar and xcexa-carrageenan. Locust bean gum is stable over a wide range of pH values, but is rapidly degraded by enzymes found in indigenous microbes.
While guar and guar derivatives have replaced locust bean gum in a number of applications because of cost-effectiveness considerations, locust bean gum is still used in dairy and frozen dessert applications, meat products, pet foods, and the textile industry.
Aloe Acemannan:
Aloe acemannan is a mannan first isolated from Aloe barbadensis (var. Miller) by McAnally at Carrington Laboratories and is pharmacologically active. In its commercial state, it contains fine water-insoluble particulates that impart turbidity to the sol. About 80% of the commercial product is a polysaccharide that is composed of a mannose backbone of from 5-50,000 linked units, with  greater than 75% being greater than 10,000. Commercial acemannan is partially water soluble and forms viscous sols. It, too, reacts synergistically with xanthan to form elastic gels and alkaline borate to form amorphous gels.
Xanthan Gum:
Xanthan gum is a so-called heteropolysaccharide obtained from the fermentation of Xanthamonas campestris. The polymer backbone is composed of (1xe2x86x924)-linked xcex2-D-glucopyranosyl units, the same as cellulose. Trisaccharide side chains are attached to alternate D-glucosyl units. These are composed of acetyl mannose, glucuronic acid, and mannose residues, with about half of the terminal mannose units containing pyruvate as a 4,6 cyclic acetal. Many commercial xanthan gum products form somewhat turbid sols, although most of the cellular debris is removed by centrifugation as a processing step. A few higher-value commercial products form an essentially clear sol as a result of an additional filtration step in the processing.
Xanthan gum imparts high viscosity to aqueous solutions at low concentrations. It is compatible with a wide pH range (1-13), being quite stable at ambient temperature for all values. Xanthan gum sols will also add viscosity to solutions having high salt content. Xanthan interacts synergistically with galactomannans, such as guar gum and locust bean gum, and konjac glucomannan to significantly increase viscosity and/or form gels. With these unique properties and its GRAS listing as a food additive, xanthan gum has a wide range of applications, from oil well drilling to salad dressings, cosmetics, and pharmaceuticals.
Clarified Hydrocolloid Composites:
Hydrocolloid composites with varying components in varying weight/weight rations can be prepared by combining their sols and then recovering the product by one of any number of available methods. Although co-processed hydrocolloids and dry physical mixtures of hydrocolloids powders exhibit essentially the same solution properties, dispersion and water absorption properties can be significantly different and vary according to the relative proportions.
Clarified Hydrocolloid/Borate Interaction Products:
At pH values between about 7.5 and 9.0, the borate ion will interact with polymers containing cis-1,2-diols to form more viscous, amorphous systems. These polymeric diols can be synthetic, semi-synthetic, or natural. Some of the more common polymers which undergo this reaction are the polyvinyl alcohols; galactomannans, such as guar gum and locust bean gum; and glucomannans, such as konjac and Aloe (ace) mannans. Depending on the concentration of the polymer, or polymers if two or more are used, the borate, and other additives, if any, the consistency can vary from somewhat viscous fluids to crisp amorphous solids. At selected concentrations of the individual components, the reaction products behave like xe2x80x9chealablexe2x80x9d solids that will flow at body temperatures. Other soluble and soluble materials can be added to impart desired properties, such as increased fluid absorption, fluid donation, elasticity, etc.
Konjac clarification:
Snow, W. C. and Renn, D. W. Clarified and cold-melt konjac glucomannan. Patent Nos. WO 09302571 (Feb. 18, 1993) and EP 646133A1 (Apr. 5, 1995). (Use of considerable heating, a variety of salts and other reagents, along with filter aid to clarify konjac and reduce turbidity (20-100 NTUs), nitrogen and UV spectral absorbance)
Ohashi, S., Shelso, G. J., Moirano, A. L., and Drinkwater, W. L. Clarified konjac glucomannan. Patent Nos. WO 09303047 (Feb. 18, 1993) and EP 00646134A1 (Apr. 5, 1995). (Use of considerable heat to dissolve and filter. Impurities precipitated using aluminum sulfate or other salts such as calcium and magnesium sulfate, filtering, then recovering using isopropyl alcohol. Reconstituted konjac has an aqueous sol turbidity potential of less that 20 turbidity units . . . )
Asahi Kasei Kogyo K K. Glucomannan eye drops. Japan Patent JP6345653 (Dec. 20, 1994). (Konjac powder, PROPOL PA, was stirred in distilled water for dissolution then centrifuged at 2000 rpm for 10 minutes after which the supernatant had a xe2x80x9cfirst grade white turbidityxe2x80x9d. This was diluted with distilled water and heated to boiling.)
Maekaji, K. The Mechanism of Gelation of Konjac Mannan. Agr.Biol. Chem. 38 (2), 315-321 (1974). (Insolubles were removed by filtration of a 0.5% sol after stirring the dispersion for two hours at room temperature, by filtration through a glass filter.)
Jacon, S. A., Rao, M. A., Cooley, H. J., and Walter, R. H. The isolation and characterization of a water extract of konjac flour gum. Carbohydrate Polymers 20, 35-41 (1993). (A 0.6% sol of konjac flour in distilled water was agitated for 1.5 hours in a temperature regulated shaker held at approximately 70xc2x0 C. Insolubles were removed by centrifugation and the supernatants coagulated in 3 volumes of 99% ethanol. Precipitate separated, washed with ethanol, then dried to constant weight at 105xc2x0 C.)
Morita, S., Morita, H., Shibata, K., and Nakayama, H. Gel for zone electrophoresis. Jpn. Kokai Tokkyo JP 04,248,460 [92,248,460]. (Clarification of a 0.4% sol by centrifugation, determination of dry weight and using clarified konjac sol directly without drying).
Nippon Chemifar Co., Ltd. Konjac glucomannan manufacture. Jpn. Kokai Tokkyo Koho JP 58,213,001 [83,213,001] (Dec. 10, 1983). (Dissolving overnight at room temperature, centrifuging, coagulating supernatant in ethanol, redissolving, centrifuging, coagulating, and freeze-drying).
Ogasawara, S. Yamazaki., and Nunomura, W. Electrophoresis on konjac mannan gel. Seibutsu Butsuri Kagaku 31(3)155-8(1987). (50% ethanol for a week, centrifuged, pellets in 80% ethanol for 3 days, centrifuged, washed, filtered. Never dissolved.)
Sugiyama, N. and Shimahara, H. Method of reducing serum cholesterol level with extract of konjac mannan. U.S. Pat. No. 3,856,945 (Dec. 24, 1974). (Konjac purified by dissolving the konjac flour in water, filtering through 150 mesh nylon then a glass filter, dialyzing and freeze-drying. Product is cloudy when reconstituted. Not a commercially viable process.)
Sugiyama, N. and Shimahara, Konjac mannan. U.S. Pat. No. 3,928,322 (Dec. 23 1975). (Dissolving in water, removing insolubles by filtration or centrifugation, freeze drying).
Sugiyama, N. and Shimahara, H. Konjac mannan. U.S. Pat. No. 3,973,008 (Aug. 3, 1976). (Dissolving in water, removing insolubles by filtration or centrifugation, dialyzing and freeze drying)
Izumi, T. et al., xe2x80x9cUse of glucomannan for the separation of DNA fragments by capillary electrophoresisxe2x80x9d Journal of Chromatography A, 652, 41-46 (1993). (use of non-deacetylated konjac as medium for capillary electrophoresis).
Ogasawara, S. et al., xe2x80x9cElectrophoresis on Konjac mannan gelxe2x80x9d Seibutsu Butsuri Kagaku 31, 155-158 (1987). (use of konjac gels for electrophoretic separations in non-denaturing buffer systems).
Morita, S. et al., xe2x80x9cGel media for zone electrophoresis of proteins or nucleic acidsxe2x80x9d Jpn. Kokai Tokkyo Koho JP 04,248,460 (Sep. 3, 1992) CA117: 248159 g (1992). (gel matrix of agarose and konjac glucomannan used for nucleic acid and protein separations in non-denaturing buffers).
Clarified Partially Depolymerized Konjac:
Tomita, M., Ono, J., Fukuwatari, Y., Mizota, T., and Nanba, K. Water-soluble dietary fibers and method for preparation of same. U.S. Pat. No. 4,971,814 (Nov. 20, 1990). (Konjac powder is partially hydrolyzed using cellulase from Aspergillus to yield dietary fibers with average M.W. of 2,000-15,000.)
Tomita, M., Shimamura, S., Fukuwatari, Y. and Nanba, K. Glucomannan hydrolysates for treatment of intestinal cancer. Japan Kokai Tokkyo Koho JP 05,246860 (Sep. 24, 1993). (Chem. Abstr, 120, 14904, 1994). (Konjac glucomannan was partially hydrolyzed using cellulase and products used as anticholesteremics and antitumor agents in the large intestine.)
Takahashi, R., Ksusakabe, I., Kusama, S., Sakurai, Y., Murakami, K., Maekawa, A., and Suzuki, T. Structures of Glucomanno-oligsaccharides from the Hydrolytic Products of Konjac Glucomannan Produced by a xcex2-Mannanase from Streptomyces sp. Agric. Biol. Chem, 48 (12) 2943-2950 (1984). (Konjac glucomannan hydrolyzed with a purified mannanase.)
Tiefenthaler, K. H. O. and Wyss, U. Water soluble guar product and method for making it, U.S. Pat. No. 4,320,226 (Mar. 16, 1982). (Depolymerization of guar gum in the presence of alkali).
Guar Gum Clarification:
Naoki, M., Shiyoujo, S., and Taku, T. Purification of galactomannan.
Japan Patent JP63101402A (Sep. 17, 1984). (Galactomannan is contacted with an alkali metal hydroxide (e.g., sodium hydroxide)in a medium comprising water or a mixture of water with a hydrophilic organic solvent The product is then neutralized with neutralizing agent (e.g., hydrochloric or sulfuric acid) to obtain the desired galactomannan.)
Mitsuo, M. Purification of Galactomannan. Japan Patent JP5239105 (Sep. 17, 1993). (An aqueous solution of crude galactomannan is blended with a chelating agent, the blended solution is filtered, the filtrate is mixed with a precipitating agent for galactomannan to recover and purify galactomannan.)
Mitsuo, M. Purification of Galactomannan. Japan Patent JP5239106 (Sep. 17, 1993). (An aqueous solution of crude galactomannan is blended with a monosaccharide, the blended solution is filtered, the filtrate is mixed with a precipitating agent for galactomannan to recover and purify galactomannan.)
Hirofumi, N., Hideki, Y., and Michiyoshi, A. Purification of galactomannan. Japan Patent JP63035606 (Feb. 16, 1988). (The pH of an aqueous solution obtained by dissolving a galactomannan-containing product such as crushed guar beans, locust beans or tara beans in hot water at 70xc2x0 C. or above is adjusted to 4.5-6.5 by adding an acid to the solution. A filter aid (e.g., Perlite) of a mean particle diameter of 15-20 microns is added to this aqueous solution. This solution is filtered to remove insoluble matter such as protein and cellulose, and a hydrophilic organic solvent such as methanol or isopropyl alcohol is added to the filtrate to precipitate gum. This gum is dehydrated by pressing, dried and ground.)
Noble, O., Turquois, T, and Taravel, F. R. Rheological Properties of Galactomannan-Based Gels. Part Ixe2x80x94Guar and Hydroxypropylguar Gels in Alkaline Media. Carbohydrate Polymers 12, 203-217 (1990). (Guar gum purified by dispersing in stirring water at 60xc2x0 C. and stirring rapidly for 1 or 2 hours. Insoluble material was removed by centrifugation and supernatants precipitated by addition of 95% isopropyl alcohol. Precipitate washed with ethanol and vacuum dried.)
Locust Bean Gum Clarification:
Braun et al., Preparation of Vegetable Gum Solutions. U.S. Pat. No. 2,144,522 (Jan. 17, 1939). (Decolorizing and clarifying locust bean gum by adding activated carbon and aluminum sulfate, filtering, and coagulating in isopropyl alcohol).
Foster, Treatment of Manno Galactan Gums. U.S. Pat. No. 3,346,556. (Oct. 10, 1967) (Example 5 discloses a means for clarifying locust bean gum by adding diatomaceous earth and filtering).
Naoki, M., Shiyoujo, S., and Taku, T. Purification of galactomannan. Japan Patent JP63101402A (Sep. 17, 1984). (Galactomannan is contacted with an alkali metal hydroxide (e.g., sodium hydroxide) in a medium comprising water or a mixture of water with a hydrophilic organic solvent The product is then neutralized with neutralizing agent (e.g., hydrochloric or sulfuric acid) to obtain the desired galactomannan.
Mitsuo, M. Purification of Galactomannan. Japan Patent JP5239105 (Sep. 17, 1993). (An aqueous solution of crude galactomannan is blended with a chelating agent, the blended solution is filtered, the filtrate is mixed with a precipitating agent for galactomannan to recover and purify galactomannan.)
Mitsuo, M. Purification of Galactomannan. Japan Patent JP5239106 (Sep. 17, 1993). (An aqueous solution of crude galactomannan is blended with a monosaccharide, the blended solution is filtered, the filtrate is mixed with a precipitating agent for galactomannan to recover and purify galactomannan.)
Hirofumi, N., Hideki, Y., and Michiyoshi, A. Purification of galactomannan. Japan Patent JP63035606 (Feb. 16, 1988). (The pH of an aqueous solution obtained by dissolving a galactomannan-containing product such as crushed guar beans, locust beans or tara beans in hot water at 70xc2x0 C. or above is adjusted to 4.5-6.5 by adding an acid to the solution. A filter aid (e.g., pearlite) of a mean particle diameter of 15-20 microns is added to this aqueous solution. This solution is filtered to remove insoluble matter such as protein and cellulose, and a hydrophilic organic solvent such as methanol or isopropyl alcohol is added to the filtrate to precipitate gum. This gum is dehydrated by pressing, dried and ground.)
Morikawa, M. and Suzuki, S. Purification of locust bean gum. JP63105004 (May 10, 1988). (Crude locust bean gum is dissolved in warm water and filtering, followed by recovering the locust bean gum and drying.)
Xanthan Gum Clarification:
Kang, K. S. and Petitt, D. J. xe2x80x9cXanthan, Gellan, Welan, and Rhamsanxe2x80x9d in Industrial Gums, Polysaccharides and Their Derivatives, Third Edition. Whistler, R. L. and BeMiller, J. N., Editors. Academic Press, 1992, page 346. (xe2x80x9cA clear product can be produced by diluting the fermentation liquor and clarifying it by filtration.xe2x80x9d)
Rinaudo, M., Milas, M., amd Kohler, N. Enzymatic clarification process for improving the injectivity and filtrability of xanthan gums. (Abstract: Enzymatic treatment, in aqueous dispersion, of a xanthan gum containing bacteria cell residues and microgels, as impurities, by means of a Basidomycete cellulase . . . , improved the injectivity and filtrability thereof.)
Murofushi, K., Nagura, S., Homma, T., and Armentrout, R. Process for preparation of a purified xanthan gum. European Patent Application No. 92311401.1 (Jun. 30, 1993). (Heat treatment followed by alkaline protease and lysozyme, then recovering the xanthan from the broth. xe2x80x9cA clear aqueous solution of the xanthan gum may be obtained without complex proceduresxe2x80x9d.)
Aloe Acemannan Clarification:
McAnnalley, B. H. Process for preparation of aloe products, products produced thereby and compositions thereof. U.S. Pat. No. 4,735,935 (Apr. 5, 1988). (Patent covering isolation of acemannan)
McAnnalley, B. H. Process for preparation of aloe products, products produced thereby and compositions thereof. U.S. Pat. No. 4,917,890 (Apr. 5, 1988). (Patent covering isolation of acemannan)
Vilkas, E. and Radjabi-Nassab, F. The glucomannan system from Aloe vahombe (liliaceae), III. Comparative studies on the glucomannan components isolated from the leaves. Biochemie 6, 1123-1127 (1986). (Aqueous sol prepared and centrifuged. Supernatant coagulated in ethanol.)
Mandal, G. and Das, A. Structure of the glucomannan isolated from the leaves of Aloe barbadensis (MILLER) Carbohydrate Research 87, 249-256 (1980). (Aqueous sol prepared and centrifuged.)
Hydrocolloid Co-processing:
Yoshida, H., Kamiya, S., Takano, Y., and Toba, S. Instant konjac mannan food. Jpn. Kokai Tokkyo Koho JP62 96,061 (May 2, 1987).(Chem. Abstracts 107, 133074 (1987). (xe2x80x9cA solution containing konjac mannan and xanthan gum (95-5:5-95) at acidic to neutral pH is dried to give an instant konjac mannan food with high water absorbency and reconstitution ratexe2x80x9dxe2x80x94konjac was not deacetylated.)
Kira, M. Preparation of agar gel (tokoroten) containing glucomannan. JPN. Kokai Tokkyo Koho JP 05, 199,853 (Aug. 10, 1993). (CA 119:224827 1993). (xe2x80x9cTokoroten with improved strength and elasticity and yet without the odor of agar is prepared by the addition of glucomannan and thickening agents into the weak alkali-treated agar. After the mixture is heated to dissolve, it can be deodorized and decolorized prior to gellingxe2x80x9d.)
Tako, M. Synergistic Interaction between Xanthan and Konjac Glucomannan in Aqueous Media. Biosci. Biotech. Biochem. 56(8), 1188-1192 (1992). (Synergistic gel formation described for native, de-pyruvated, and de-acetylated clarified xanthan and clarified konjac. For clarification of the xanthan, a 0.1% sol of commercial xanthan in distilled water was heated at 90xc2x0 C. for 30 minutes, then cooled to room temperature and filtered through Celite 545. The filtrate was made to 0.1% with KCl, coagulated in 2 volumes of ethanol, the precipitate collected and dried in vacuo. The konjac flour was soaked in 50% ethanol for three days at room temperature. The suspension was filtered and the residue was dissolved by stirring with distilled water at 90xc2x0 C. for 30 minutes. The sol was filtered through Celite 545 and the clear filtrate coagulated in 2 volumes of ethanol. The precipitate was collected and dried in vacuo.
Nippon Chemipharm. Manufacture of konnyaku glucomannan for electric migration gel materials. Jpn. Kokai Tokkyo Koho JP58, 213,001 (Dec. 10, 1983). (Purification by forming a sol, centrifuging, and coagulating the supernatants in ethanol.)
Kawano, N. Instantly Soluble Glucomannan Composition, Its Use and Preparation. Japan Patent Disclosure No. H5-38263. (Feb. 19, 1993). (Fluidized bed granulation and drying of mixed polysaccharides, including konjac.)
Fujihara, K. and Nakagawa, T. Method of producing readily soluble polysaccharides. Japan Patent Disclosure No: 1982-[Showa]-28.203 (Feb. 15, 1982). (Dissolving polysaccharides or mixtures and spray-drying. Only mixture given is locust bean gum/xanthan.)
Musson, G. D. and Prest, C. T. Thermo-irreversible edible gels of glucomannan and xanthan gums. U.S. Pat. No. 4,894,250 (Jan. 16, 1990). (preparation of deacetylated konjac gels containing xanthan and, optionally, carrageenan, pectin, algin, agar, gellan, and/or guar)
Fukuda, T. Manufacture of dried konjac with mono- and/or oligosaccharides Japan Kokai Tokkyo Koho JP 04 08,257 (Jan. 13, 1992) CA 116:172746c (1992). (Dry konjac is manufactured by mixing konjac with mono- and/or oligosaccharides and drying. Rehydration in water restores its original gel state)
Kawano, K. Instantly soluble glucomannan composition, its use and preparation Japanese Unexamined Patent Application Disclosure H5-38263 (Feb. 19, 1993) WPI Acc No: 93-096400/12. (Non-deacetylated konjac is co-processed with a variety of hydrocolloids (carrageenan, xanthan, agar, alginates, pectin, starch CMC, polyacrylates, etc.) by mixing in the fluid state, then drying to give products that are readily dispersible and soluble in water)
Renn, D. W., Lauterbaugh, G. E., and Hemmingsen. P. Soluble dried cassia alloy gum composition and process for making same U.S. Pat. No. 4,952,686 (Aug. 28, 1990). (The initial patent on the technique of co-processing insoluble or poorly soluble hydrocolloids with one or more other hydrocolloids to impart solubility or other important properties. Clarified Cassia galactomannan coprecipitated with various gums to improve solubility of the galactomannan. Composite of clarified Cassia gum and xanthan is highly water absorbent.)
Snow. W. C. and Renn, D. W. Glucomannan spongeous matrices. Patent Nos. WO 09402029A1 (Feb. 3, 1994) and EP 650348A1 (May 3, 1995). (Konjac co-processed with agar or at least one other gelling polysaccharide to form a spongeous matrix)
Yoshida, H. et al.. Instant Konjak mannan food Jpn. Kokai Tokkyo Koho JP 62 96,061 (May 2, 1987) CA 107: 133085f (1987). (Solution of konjac mannan and xanthan at acidic to neutral pH was dried to give an instant konjac mannan product with high water-absorbency and reconstitution ratexe2x80x94konjac was not deacetylated)
Applegren, C. H. Process for preparing a product comprising guar-gum U.S. Pat. No. 4,754,027 (Jun. 28, 1988). (Guar composites produced by granulating non-clarified guar with sols of non-gelling hydrocolloids.)
Toba, S., Yoshida, H., and Tokita, T. Konjac mannan-containing reversible gel. U.S. Pat. No. 4,676,976. (Jun. 30, 1987). (Reversible konjac/xanthan gel formation with strongest gels at 4:1 ratio)
Ishikawa, H. et al. Preparation of freeze-resistant konjac. Japanese Patent Application No. 60-4019, Filed Jan. 16, 1985, Abstract published Dec. 12, 1986. (Co-processed, but not dried, deacetylated konjac and insoluble alginate)
Ueno, K. Preparation of konjak resistant to freezing. Jpn. Kokai Tokkyo Koho JP 05 00,055 (Jan. 8, 1993) CA118: 146606d (1993). (xe2x80x9cKonjak resistant to freezing is prepared by adding starch and natural gums, e.g., locust bean gum and tara gum.xe2x80x9d)
Umehara, S. et al., A dry gel containing starch and konnyaku mannan as an instant konnyaku Jpn. Kokai Tokkyo Koho JP 62, 259,550 (Nov. 11, 1987) CA108: 149158p (1988). (dried gel of deacetylated konjac and starch that hydrates to gel particles in boiling water.)
Vernon, A. J. et al., Thermo-irreversible gelling system and edible materials based thereon European Patent Application Publication No.: 0 050 006 (Jul. 10, 1981). (konjac and carrageenan gelled using phosphate buffer and heat)
Suto, S. et al., Scanning electron microscopy of blend of konjac mannan and hydroxypropyl cellulose. Sen-I Gakkaishi 48(8) 437-440 (1992). (gel prepared from blend of konjac and hydroxypropyl cellulose)
Ikeda, M. and Harada, S. xe2x80x9cLow calorie processed food made with gel particles of glucomannan coagulumxe2x80x9d U.S. Pat. No. 5,213,834 (May 25, 1993). (encapsulated organic acids to neutralize alkaline gels of konjac and konjac gels made with the addition of other hydrocolloids, such as carrageenan, alginates, locust bean gum, agar, xanthan, etc.)
Kawano, N. Instantly soluble glucomannan composition, its use and preparation. Japanese Unexamined Patent Application Disclosure H5-38263 (Feb. 19, 1993) WPI Acc No: 93-096400/12. (non-deacetylated konjac is coprocessed with a variety of hydrocolloids (carrageenan, xanthan, agar, alginates, pectin, starch CMC, polyacrylates, etc.) by mixing in the fluid state, then drying to give products that are readily dispersible and soluble in water)
Hydrocolloid Films, Foams, Gels, and Sponges:
D. A. Harper, J. H. Morgan, S. Nochumson, M. V. Ostrovsky, D. W. Renn, W. C. Snow. xe2x80x9cAgarose compositions for nucleic acid sequencingxe2x80x9d U.S. Pat. No. 5,455,344 (Oct. 3, 1995). (Sequencing nucleic acids using a polysaccharide gel medium in the presence of denaturing agentsxe2x80x94includes deacetylated konjac gels)
Snow. W. C. and Renn, D. W. Glucomannan spongeous matrices. Patent Nos. WO 09402029A1 (Feb. 3, 1994) and EP 650348A1 (May 3, 1995). (Konjac co-processed with agar or at least one other gelling polysaccharide to form a spongeous matrix upon freezing and thawing)
Masao, K. Glucomannan/polyhydric alcohol composition and film prepared therefrom. European Patent Application Publication No. 0 273 069 (Jun. 7, 1988). (Konjac glucomannan films and applications.)
Kakizaki, T. and Kdubodera, M. Edible glucomannan film for food packing. Jpn. Kokai Tokkyo Koho JP 62,126,950 (Jun. 9, 1987). (CA107, 613, (1987). (xe2x80x9cA composition containing glucomannan, optionally other natural polysaccharides, and one or more of polyhydric alcohols, sugar alcohols, monosaccharides, disaccharides, and oligosaccharides is kneaded, dissolved in water, and made into a film to produce an edible film for food packagingxe2x80x9d).
Merritt II, F. M. Edible film and method. U.S. Pat. No. 5,962,053. (Oct. 5, 1999). (Abstract: Described is an edible, water insoluble film which is a blend of polysaccharide and protein and, in particular, a ternary blend of konjac flour as a major constituent, agar and gelatin. Also described is a method of forming the film including a deacetylating step to insolubilze the konjac flour.)
Nussinovitch, A. Sponge comprising expansion product of hydrocolloid. WO 9417137 A (Aug. 4, 1994). (xe2x80x9cSponge is formed by foaming one or more hydrocolloids selected from agar, carrageenan, gelatin, alginate, starch, pectin, gellan konjak, mannan or xanthan locust bean gum. The sponge containing a plasticiser (esp. glycerol, sorbitol or other polyol, a sugar or sugar substitute, bubbles of a gas other than air and opt. a flavoring agent or taste enhancer.xe2x80x9d)
Tanabe, O et al. , Fiber-rich foods made from Konjak flour. Jpn. Kokai Tokkyo Koho JP 01, 256,366 (Apr. 4, 1988) CA113: 57776p (1990). (water-insoluble, gelled deacetylated konjac recovered by freeze thawingxe2x80x94not dried)
Sakamoto, J and Tanuma, H. Low-calorie food products containing konjac mannan and processes for preparing the same U.S. Pat. No. 5,116,631. (non-deacetylated konjac as a foam stabilizer for egg white meringues).
Ford, D. M. and Cheney, P. A., xe2x80x9cAir or oil emulsion food product having glucomannan as sole stabilizer-thickenerxe2x80x9d U.S. Pat. No. 4,582,714. (non-deacetylated konjac as a aerated food stabilizer)
Nozaki, H. et al. Devil""s tongue-containing whip cream. Japanese Patent Application No. 01-177050, Filed Jul. 11, 1989, Abstract published May 7, 1991. (prepared alkaline deacetylated gel added to cream while whipping)
Sawaguchi, K. Meringue. Japanese Patent Application No. 57-126718, Filed Jul. 22, 1982, Abstract published May 12, 1984. (use of non-deacetylated konjac to stabilize meringues)
Sugino, Y. Porous gel foods and their manufacture from glucomannan and whipped egg white. Jpn. Kokai Tokkyo Koho JP 04 11,85 (Jan. 16, 1992). (egg white/konjac whipped together then set (deacetylated) with calcium hydroxide and heat)
Bakis, G. et al., xe2x80x9cProduction of polysaccharide foam comprises mechanically foaming aqueous solutions of soluble polysaccharide, e.g., alginate, hyaluronate, carrageenan, chitosan or starchxe2x80x9d WO 9400512 (Jan. 6, 1994) WPI Acc No: 94-026166/03. (mechanically foaming an aqueous solution of a polysaccharide and used as wound dressing etc.)
Borate Interaction Products:
Renn, D. W. Solid borate-diol interaction products for use in wounds. World Patent WO 09953968A1 (Oct. 28, 1999). (Interaction of sodium tetraborate with PVA and polysaccharides, glucomanans and galactomannans, having a cis 1,2-diol configuration in their structure).
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Rademacher, K. and Fritsce, U. (Sebapharma) Dressing system. WO 9203172. Feb. 20, 1992. (The bandage, dressing or support matrix consists of a biocompatible, open-pored plastic foam with a hydrogel embedded in the pores. The hydrogel is formed from a borate-modified Guar gum . . . )
The invention is directed to a process of producing a clarified hydrocolloid which, when hydrated, forms a clear sol, the said process comprising: (a) soaking a hydrocolloid-containing material dispersed in water until the hydrocolloid is hydrated; (b) stirring the hydrated hydrocolloid until a homogenous particulate-containing sol is obtained; (c) removing the insoluble particulates to produce a clarified sol; (d) removing any remaining particulates in the clarified sol by filtration; and (e) recovering clarified hydrocolloid directly from the filtrate.
The insoluble particulates in step (c) can be removed by centrifugation or by coarse filtration.
The hydrocolloid can be selected from the group consisting of konjac glucomannan, guar gum, locust bean gum, aloe mannan, agar, agarose, algins, xcex2-, xcexa-, xcex- "igr"-carrageenans, chitosan, collagen, curdlan and other xcex2-1,3-glucans, fig seed gum (galacturonan), gellan, hyaluronic acid, pectins, Rhizobium gum, Porphyridium cruentum polysaccharide, starches (amylose, amylopectin), acacia gum, gum arabic, chondroitin sulfates, dextrans, flaxseed gum, gum ghatti, inulin (fructan), karaya gum, larch arabinogalactan, levan (fructosan), cassia gum, tara gum, fenugreek gum, oat glucans, okra mucilage, psyllium seed gum, pullulan, quince seed gum, rhamsan, scleroglucan, succinoglucan, tamarind gum, gum tragacanth, wellan, and xanthan gum.
In cases where the hydrocolloid is insoluble at ambient temperature, the hydrated colloid can be heated to solubilize the hydrocolloid before proceeding with step (c).
When the hydrocolloid is konjac glucomannan, the hydrated konjac can be heated to a temperature of less than or equal to about 45xc2x0 C.
In conducting step (b) the hydrated colloid can be shear-stirred until a homogenous sol is obtained. Furthermore, in conducting step (e), water-miscible alcohol can be added to the solution.
The hydrocolloid recovered from the filtrate in step (d) can be dried to form a solid. The hydrocolloid after drying can be ground to a consistency of about 100 mesh.
The viscosity of the clarified hydrocolloid sol obtained after the performance of step (e) can be within about 70 to 90 percent of the viscosity of the untreated hydrocolloid sol at equivalent hydrocolloid concentration.
The sol of one or more other hydrocolloids can be added before recovery to yield clarified hydrocolloid composites.
A second clear hydrocolloid sol can be added before step (e) is performed. Alternatively, a second unclarified hydrocolloid sol can be added before step (c). Furthermore, a dry first hydrocolloid and a second dry hydrocolloid can be mixed before performing step (a).
The invention is also directed to a process of producing a hydrocolloid which when hydrated forms a clear sol comprising soaking the hydrocolloid in water until the hydrocolloid is hydrated, shear-stirring the hydrated hydrocolloid until the homogenous particulate-containing sol is obtained, centrifuging the sol to remove any filter-blinding material, adding a filter aid to the centrifugate, filtering the centrifugate at a temperature less than about 45xc2x0 C., recycling the filtrate until it is clear, recovering the clarified hydrocolloid by miscible alcohol coagulation, and maintaining re-solubility characteristics of the clarified hydrocolloid by washing with high titer alcohol.
The invention includes a process of producing a konjac glucomannan which, when hydrated, forms a clear konjac glucomannan sol which comprises dispersing a konjac containing flour in water, permitting the dispersed konjac-water mixture to stand at room temperature until the konjac is hydrated, subjecting the hydrated konjac mixture to a high shear stirring action to produce a smooth sol, centrifuging the smooth sol to remove insoluble particulates in the mixture, adding a filter aid to the filtrate and mixing the filter aid into the mixture, filtering the mixture at a temperature less than 45xc2x0 C. to obtain a clear filtrate, treating the clear filtrate with isopropyl alcohol to coagulate the konjac glucomannan, collecting the konjac coagulated konjac, and drying the konjac.
The invention also incorporates a process of producing a guar gum which when hydrated forms a clear guar gum sol, which comprises dispersing a guar gum containing material in water by first wetting the material with isopropyl alcohol and then adding water to the mixture, heating the mixture with stirring until homogenous and hydration of the guar is complete, centrifuging the mixture, adding a filter aid to the mixture and mixing the filter aid thoroughly into the mixture, filtering the mixture, adding an isopropyl alcohol to the filtrate obtained from the filtration step, collecting coagulated guar gum, drying the guar gum and grinding the collected coagulated guar gum into a powder.
The invention is also directed to a process of producing a locust bean gum powder which when hydrated forms a clear locust bean gum sol comprising adding a locust bean gum containing material to water, heating the locust bean gum-water mixture to the boiling point, stirring the mixture until a homogenous mixture is obtained, centrifuging the mixture, adding a filter aid to the centrifugate, mixing the mixture until homogeneous, filtering the mixture to obtain a clear filtrate, adding isopropyl alcohol to the filtrate to coagulate the locust bean gum, collecting the coagulated locust bean gum, drying the coagulated locust bean gum and grinding to yield a powder.
The invention includes in a further embodiment a process of producing an aloe mannan which when hydrated forms a clear aloe sol comprising adding an aloe mannan containing material to water, permitting the aloe-water mixture to stand until the aloe mannan is hydrated, raising the temperature of the aloe-water mixture to the boiling point, mixing the mixture until a homogenous mixture is obtained, centrifuging the mixture to remove undesirable particulates, adding a filter aid to the centrifugate, filtering the mixture, coagulating the aloe mannan by adding a miscible alcohol to the mixture, collecting the coagulated aloe mannan, drying the coagulated aloe mannan and grinding it to obtain a powder.
The invention is also directed to a process of producing a xanthan gum which when hydrated forms a clear xanthan gum sol comprising dispersing a xanthan gum containing material in water, heating the xanthan-water mixture to the boiling point, mixing the mixture until homogeneity is obtained, centrifuging the mixture to remove undesirable particulates, adding a filter aid to the mixture, heating to boiling, filtering the mixture, coagulating the xanthan by adding a miscible alcohol to the filtrate, collecting the coagulated xanthan gum and drying the coagulated xanthan gum and grinding it to obtain a powder.
The invention in a further version includes a process of producing a hydrocolloid composite which when hydrated forms a clear hydrocolloid composite sol comprising dispersing a first clarified hydrocolloid and at least a second clarified hydrocolloid in water, adding sodium chloride to the sol, mixing the mixture to obtain a homogenous mixture, and coagulating the first hydrocolloid with the second hydrocolloid as a precipitate by adding a miscible alcohol, collecting the coagulated hydrocolloid composite, drying the composite and grinding it to form a powder.
The invention is also directed to a clarified hydrocolloid or a composition comprising clarified konjac and clarified guar gum which composition forms a clear sol when mixed with water, a composition comprising clarified konjac and clarified xanthan gum which composition forms a clear sol when mixed with water, a composition comprising clarified xanthan gum and clarified guar gum which composition forms a clear sol when mixed with water, a composition comprising clarified aloe mannan and clarified guar gum which composition forms a clear sol when mixed with water, a composition comprising clarified konjac and clarified agar which composition forms a clear sol when mixed with water, a composition comprising clarified aloe mannan and clarified konjac which composition forms a clear sol when mixed with water, a composition comprising clarified konjac and clarified carboxymethyl cellulose which composition forms a clear sol when mixed with water, or a composition comprising clarified guar gum and clarified carboxymethyl cellulose which composition forms a clear sol when mixed with water.
The invention is also directed to a process of forming low sol viscosity hydrocolloids by having the particulate hydrocolloids absorb hydrogen peroxide and then heating the hydrocolloids or permitting the hydrated colloids to remain at room temperature for an extended period.
The invention includes a process of producing a reduced viscosity konjac which comprises adding hydrogen peroxide to the konjac-containing solid, blending the mixture until a homogenous paste is obtained, heating the paste to about 65xc2x0 C. for about five hours, cooling the mixture to about room temperature, adding a filter aid to the mixture, filtering the mixture to obtain a clear filtrate, adding isopropyl alcohol to the clear filtrate to precipitate konjac, and collecting the coagulated konjac, drying the coagulated konjac and grinding it to form a powder.